Tiagabine

Actions

• Acts as a GABA reuptake inhibitor by blocking the GABA transporter 1 (GAT-1).

Metabolism

Hepatic

Enzymes involved

• CYP3A4

Elimination

Fecal ~63%

Therapeutic serum concentration range

5-70 μg/ml

Half-life

5-13 hours

Plasma protein binding

96%

Important side-effects

Suicidal behavior and ideation.

Cognitive/Neuropsychiatric adverse events.

Spectrum

Adjunctive therapy in focal seizures with or without generalization.

Dosing recommendation

Start with 4 mg/day in a single dose.

Increased by 4-8 mg/day at weekly intervals.

Target dose: 30-50 mg/day divided in two 2-4 doses.

Renal impairment

No dose adjustment is necessary in patients with impaired renal function.

Hepatic impairment

Patients with moderate (Child-Pugh class B) and severe (Child-Pugh Class C) hepatic impairment require adjustment of the initial and target doses.